Researchers identify two very different groups of children with an elevated likelihood of receiving a delayed ASD diagnosis

While many children with autism spectrum disorders (ASD) receive a diagnosis by the time they reach preschool age, approximately 25% are not diagnosed until they are more than six years old—a delay that can significantly reduce the effectiveness of interventions. According to a study by researchers in Israel and the United States, these late-diagnosed children tend to fall into two distinct categories.

Dan Aizenberg and colleagues analyzed data on 23,632 autistic children included in the SPARK phenotype dataset. They detected two “robust” groups of children who received ASD diagnoses after six years of age. The first group consisted of children with lower-than-average support needs and fewer comorbidities compared to early diagnosed children. The second group, in contrast, consisted of children with higher-than-average support needs and comorbidities compared to early-diagnosed children, making it likely that these children’s autism was initially misdiagnosed as a different condition.

The researchers say their findings support the existence of two opposite groups of autistic individuals at elevated risk for delayed identification and “may help guide clinicians making differential diagnoses, thereby enabling more timely and accurate diagnoses.”

Citations

“Data-driven characterization of individuals with delayed autism diagnosis,” Dan Aizenberg, Ido Shalev, Florina Uzefovsky, and Alal Eran, JAMA Pediatrics, January 13, 2025 (online). Address: Alal Eran, Computational Health Informatics Program, Boston Children’s Hospital, 300 Longwood Ave, Boston, MA 02115, [email protected].

—and—

“Delayed autism diagnoses found in two groups of children—researchers explain why,” news release, Ben Gurion University of the Negev, February 11, 2025.